diff --git a/api/client-server/content-repo.yaml b/api/client-server/content-repo.yaml
index 3c2003444..b86b6596b 100644
--- a/api/client-server/content-repo.yaml
+++ b/api/client-server/content-repo.yaml
@@ -290,12 +290,12 @@ paths:
           schema:
             type: object
             properties:
-              upload_size:
+              m.upload.size:
                 type: number
                 description: "The maximum size an upload can be in bytes."
           examples:
             application/json: {
-                "upload_size": 50000000
+                "m.upload.size": 50000000
               }
       tags:
         - Media